Tidal power

School project on sustainable development for the bilingual section of Technology at the IES Praia Barraña school in Boiro, Galicia, Spain. March, 2016.

2. Index
•Definition
•Methods:
-Tidal barrage (diagram, operation, advantages and disadvantages)
-TSG (diagram, operation, advantages and disadvantages)
-DTP (diagram, operation, advantages and disadvantages)
-Tidal lagoon (diagram, operation, advantages and disadvantages)
•Production in Europe
•Use (worldwide, Europe and Spain)
•Conclusions
•Credits

3. Definition of tidal power
It's the energy that makes use of tides to
generate electricity.
These power plants are in an experimental
stage and their level of production is still very
low.

4. Methods of generating tidal energy
•Tidal barrage
•Tidal stream generator (TSG)
•Dynamic tidal power (DTP)
•Tidal lagoon

5. Diagram of a tidal barrage

6. How does a tidal barrage operate?
A tidal barrage uses the potential energy
produced by the difference in height between
high tides and low tides.

7. Advantages and disadvantages
of tidal barrages
Advantages:
- They don't produce any waste or greenhouse gases.
- Tides are predictable.
- The energy that they produce is renewable.
Disadvantages:
- The high cost of the infrastructure.
- Global shortage of viable sites.
- Environmental issues.
- Tidal barrages only produce energy for about 10 hours a day.

8. Diagram of a tidal stream generator

9. How does a tidal stream
generator operate?
Tidal stream generators make use of the kinetic
energy of the water which comes up and down
with the tide by moving the turbines.

10. Advantages and disadvantages
of tidal stream generators
Advantages:
- They are low-cost compared with tidal barrages.
- They have a smaller ecological impact than tidal barrages.
- They don't produce any waste or greenhouse gases.
- Tides are predictable.
- The energy that they produce is renewable.
Disadvantages:
- Grid connection.
- The pipes can be dangerous for animals and humans.

11. Dynamic tidal power
DTP advantages:
- No areas are enclosed.
- It doesn't produce any waste or greenhouse gases.
- Tides are predictable.
- It’s a renewable source of energy.
DTP disadvantages:
- It’s very expensive.
- Global shortage of viable sites.
DTP is an untried but promising technology
that would exploit an interaction between
potential and kinetic energies in tidal flows.
It means that very long dams (30–50 km
long) would be built from the coast straight
out into the sea or ocean.

12. Tidal lagoon
Advantages:
- It doesn't produce any waste or greenhouse gases.
- Tides are predictable.
- Renewable resource.
Disadvantages:
- It’s more expensive than tidal barrages.

A newer tidal energy design option is to construct
circular retaining walls embedded with turbines that
can capture the potential energy of tides.
The reservoirs created are similar to those of tidal
barrages.

13. Production in Europe
The production of tidal energy in Europe is so low
that it isn’t usually represented in graphics or it
appears under the category of “others”.

14. Use of tidal energy in Spain
In Spain it's used on a trial basis in Mutriku (Gipuzkoa)
and on the shores of Santoña (Cantabria).

15. Use of tidal energy in Europe
The biggest tidal energy power
station in Europe is located on
the mouth of River Ranch in
France. It has been operational
since 1967, with a power of
240MW, covering the energetic
needs of 10,000 homes in the
French region of Britanny.
This energy is frequently used in the UK too.

16. Use of tidal energy worldwide
The biggest tidal energy plant
in the world is in south Korea,
the new Sihwa Lake Tidal
Power Station, with 254MW.
Tidal energy is used in other countries like Japan, China,
Australia, Canada or New Zealand.

17. Conclusions
Although tidal energy is a clean, predictable and
renewable energy, it has three drawbacks: very
expensive infrastructures, limited availability of sites with
the specific requirements and an insufficiently developed
technology.
Its efficiency is also lower than other energies (wind,
hydraulic, solar, etc.).
In the next few years, new advances, research and the
construction of cheaper infrastructures will make tidal
energy more usual because of its predictability.

18. Credits
Done by:
Sabela Martínez Tomé
Laura Pérez López
Pablo Manuel Piñeiro Insua
Bilingual section of Technology
Group 3º ESO-B
IES Praia Barraña – Boiro (Spain)
March, 2016